The present invention relates to improvements in methods of and in apparatus for supplying nails to shoe lasting and like machines, and more particularly to improvements in methods of and in apparatus for supplying so-called tacks which can be used to fix shoe uppers and/or other parts of articles of footwear on lasts or analogous supports.
German Pat. No. 721,061 to Alter discloses an apparatus for supplying tacks to shoe heel and shoe tip lasting machines. A rotor has a set of receiving means for tacks and is indexible to a plurality of different angular positions in each of which a different receiving means is ready to accept a tack. Each such indexing operation involves an angular movement of the rotor from a predetermined starting position through a predetermined angle so that a selected number of receiving means can move into register with the discharge end or ends of one or two slideways which can feed tacks to the rotor. The angle must be changed if the rotor is to accept a larger or a smaller number of tacks. Each adjustment necessitates complete stoppage of the apparatus (and of the entire lasting machine) and a resetting of the mechanical transmission in the mechanism which serves to drive the rotor. All this takes up much time so that the apparatus is idle for relatively long intervals. Moreover, repeated back and forth movements of the rotor to and from its starting position also take up substantial amounts of time and contribute to wear upon the moving parts and their bearings. Still further, the rotor cannot be used to capacity because the receiving means are distributed only along a certain portion of its periphery. The means for receiving tacks from the rotor includes a housing with grooves which are axially offset relative to the receiving means of the rotor. Therefore, the rotor must be moved axially preparatory to transfer of a selected number of tacks into the housing. This, too, contributes to a reduction of the output of the patented apparatus.
Published German patent application No. 1,785,305 of Bumbalek discloses a tack supplying apparatus with two chutes which deliver tacks into discrete channels discharging into a common outlet for delivery of tacks to the lasting machine. The discharge ends of the chutes are adjacent elastic holders which tend to engage the adjacent tacks to thus block the admission of tacks into the respective channels. Reciprocable studs are provided to lift the holders off the discharge ends of the respective chutes in order to permit the tacks to descend into the adjacent channels. The output of the apparatus which is disclosed by Bumbalek is low.